Michael Barnes - Spine and Orthopaedic Surgeon
Private Service, Orthopaedics, Paediatrics, Spinal
DECOMPRESSION FOR LUMBAR SPINAL STENOSIS
- Normal ageing of the spine leads quite commonly to a narrowing of the spinal canal.
- As the spinal canal continues to narrow, a point may be reached where nerve pain develops in the lower extremities, sometimes precipitated by injury. Early symptoms may subside with time but more often tend to recur, persist or worsen with progression of spinal canal narrowing.
- Spinal stenosis, when it causes symptoms, may cause constant sciatica or sciatica which occurs with standing and walking and is relieved only by resting or sitting down.
- In most cases it is necessary to remove the joints at the back of the spine and the spine is then stabilised by insertion of two screws into each vertebrae (pedicle screws) joined by rods.
- Patients usually rest in bed the day after surgery and stand to take a few assisted steps on the second day after surgery.
- Surgery for spinal stenosis is performed to address an existing problem in an ageing spine. Surgery has an 85% to 90% success rate but does not stop the spine ageing and, depending upon the age of the patient, up to 5% - 10% of patients may require further surgery in the future as other segments of the spine continue to age.
Frequently Asked Questions
I am still experiencing some sciatica or numbness after my operation should I worry about this?
Only a minority of patients experience complete relief of sciatica from the time of the surgery. Most patients notice that it is much improved but there is still some aching in the leg because the nerve has a “memory” for the pain and remains slightly irritable. This usually resolves within a matter of weeks.
What do I do with the dressing?
The stitches are under the skin and will dissolve. The dressing is waterproof and you can shower in it. One week after leaving hospital simply peel it off as if it were a big band aid. Under the dressing you will find steri strips (tapes) holding the skin edges together. These may come off with the dressing but otherwise remove them one week later if they have not fallen off.
Will I need physiotherapy treatment?
Most patients undergoing a decompression operation do not have physiotherapy treatment; they simply increase their walking progressively and ease back into normal activity as their symptoms subside over a period of weeks or months. Some patients however, prefer to work with a physiotherapist and you should feel free to arrange physiotherapy if that is your preference.
When can I resume activities such as lifting?
The spine is held together by very strong screws and rods and cannot be damaged by activity, even lifting. Heavy lifting should obviously not be undertaken until your back feels strong enough. The patients who make the best recovery simply listen to their body and exercise common sense. As the weeks pass activity is increased progressively but not to the point where it causes excessive pain which can slow your progress. Full recovery takes at least three to four months and sometimes six months or more.
Normal ageing of the spine leads quite commonly to a narrowing of the spinal canal. The spinal canal narrows as a result of changes in multiple tissues but particularly degenerative arthritis involving the joints at the back of the spine (facet joints) resulting in enlargement of the joints and encroachment into the spinal canal.
In some patients degenerative arthritis of the facet joints results in a loss of their restraining function and a slippage of the spine (degenerative spondylolisthesis).
Narrowing of the spinal canal with ageing does not usually cause symptoms in the early stages because of spare capacity in the spinal canal and because the spinal nerves can, up to a point, tolerate a smaller space.
As the spinal canal continues to narrow, a point may be reached where nerve pain develops in the lower extremities, sometimes precipitated by injury. Early symptoms may subside with time but more often tend to recur, persist or worsen with progression of spinal canal narrowing.
Spinal stenosis, when it causes symptoms, may cause constant sciatica or sciatica which occurs with standing and walking and is relieved only by resting or sitting down. In severe cases patients can walk only short distances and are disabled to the same degree as patients requiring joint replacement surgery because of hip or knee arthritis. Patients often adopt a stooped posture in an attempt to open up the spinal canal and create additional space for the spinal nerves.
Surgery is performed under general anaesthetic. Optical magnification (microsurgery) is used to remove bone and tissue and to create space for the nerves.
The operative time varies from one to four hours, depending upon the number of levels requiring decompression and whether or not instrumentation (stabilisation of the spine with screws and rods) is required.
In most cases it is necessary to remove the joints at the back of the spine and the spine is then stabilised by insertion of two screws into each vertebrae (pedicles screws) joined by rods. Pedicle screw stabilisation of the spine is a very safe and routine procedure which has been performed for over twenty years and is performed most weeks by committed spine surgeons. It is always accompanied by a fusion (joining the vertebrae bone to bone). In spinal stenosis the bone removed from the spine to create space for the nerves is used to perform the fusion, often supplemented by a Tri calcium Phosphate or collagen product.
Bone grafts from the pelvis (hip) are avoided.
Post Operative Course
Patients usually rest in bed the day after surgery and stand to take a few assisted steps on the second day after surgery.
On day three patients are usually walking to the toilet and the urinary catheter is removed.
Patients usually go home on day four or five when their pain is under control with oral tablets, when they are able to get in and out of bed and up and down stairs.
Walking is the only exercise that is necessary when recovering from surgery for decompression of lumbar spinal stenosis. Walking is increased progressively with the aim of walking 1km to 2km outside within two weeks of surgery. Some patients might also have physiotherapy treatment but this is not necessary for most patients.
Sitting or standing in one position can be uncomfortable for several weeks – simply move about or change position.
Most patients notice almost immediately that there is a marked improvement in the nerve pain in the lower extremities, but in some patients there is some residual pain which slowly resolves over a month or two.
Obviously there is lower back pain and stiffness created by the surgery which resolves over weeks, tailing off over several months.
You will leave hospital with a waterproof dressing which should be removed one week later. Simply peel off this dressing as if it was a big "band aid”. The stitches under the skin dissolve. No suture removal is necessary.
Driving is normally resumed within three to six weeks when it feels safe and comfortable.
Surgery for spinal stenosis is performed to address an existing problem in an ageing spine. Surgery has an 85% to 90% success rate but does not stop the spine ageing and, depending upon the age of the patient, up to 5% - 10% of patients may require further surgery in the future as other segments of the spine continue to age.
Infection or nerve injury can occur during surgery for spinal stenosis but are extremely uncommon in my Practice.
A dural tear can occur because in spinal stenosis the dura (the membrane containing the spinal nerves and spinal fluid) can be very thin and adherent to the walls of the spinal canal. Dural tears occur occasionally and when they occur need to be repaired watertight with fine stitches. If this repair does not hold a headache or leakage of fluid out of the incision can occur and this may require further surgery. In my practice a second operation to repair a dural tear occurs approximately once every five years. Note that I perform three to four hundred spinal operations per year.
The screws which stabilise the spine (pedicle screws) are occasionally misplaced with the result that the screw contacts a nerve and causes sciatica pain. Approximately once every five years in my practice a second operation is required to remove a pedicle screw.
Patients are often elderly with co-existing medical problems such as heart problems which could present anaesthetic risks or lead to post operative complications.